Base frame for a printing press

ABSTRACT

The base frame of an offset printing press consists of two sidewalls made from steel tubing reinforced by ribs and connected by a rigid horizontal tube approximately centered in each sidewall. The diameter of the tube is about one-half of the sidewall height so that it provides good rigidity to the frame. It houses the electric drive motor and the air pump for the press.

United States Patent [72] Inventors Jaroslav Janecek Brno; Antonin Svoboda, Adamov, both of Czechoslovakia [2]] Appl. No. 773,899 [22] Filed Nov. 6, 1968 [45] Patented Jan. 11, 1972 [73] Assignee Adamovske strojirny,narok1ni podnik Adamov, Czechoslovakia m [54] BASE FRAME FOR A PRINTING PRESS 5 Claims, 2 Drawing Figs.

52 U.S. c1 101/1, 248/13, 248/19 [51] Int. Cl F16! H00 [50] Field of Search 101/1; 143/132;310/88, 89;248/13, 19,23

[56] References Cited UNITED STATES PATENTS 1,893,463 1/1933 McLain 101]] 2,990,862 7/1961 Ruben 143/132 X 3,062,350 11/1962 Demmel.. 197/17 3,096,798 7/1963 Pugsley 143/132 X Primary Examiner- Edgar S. Burr Allomey-Richard Low ABSTRACT: The base frame of an offset printing press consists of two sidewalls made from steel tubing reinforced by ribs and connected by a rigid horizontal tube approximately centered in each sidewall. The diameter of the tube is about onehalf of the sidewall height so that it provides good rigidity to the frame. It houses the electric drive motor and the air pump for the press.

BASE FRAME FOR A PRINTING PRESS BACKGROUND OF THE INVENTION This invention relates to printing machines, and particularly to supporting frames for printing presses.

Most printing presses have relatively heavy parts which perform oscillating or reciprocating motions during the normal operation of the press. The machines are normally provided with very heavy frames to hold vibrations to a minimum. Vibrations would not only reduce the useful life of the machine, but also adversely affect the quality of the printed material produced. It has been customary, therefore, to make the frames, or at least the lower portions of the frames, hereafter referred to as base frames, of heavy ferrous castings. Their cost and weight materially increase the purchase price of a printing machine, and installation of the presses is limited to suitably constructed buildings.

Welded base frames have been resorted to for reducing the weight, but the welded frames are even more costly than heavier cast iron frames of equal rigidity. The frames of relatively small offset printing presses have been made of welded tubing which is inexpensive and light in weight. Such tubular frames, however, do not have adequate stability and rigidity to permit operation at very high speeds without a significant sacrifice in the quality of the printed work due to vibration of the press.

The object of the invention is the provision of a base frame for a printing press, more specifically an offset press, which combines relatively low weight with high flexural and torsional rigidity, and thus combines the advantages of the light, welded tubular frames with those of the heavy cast iron frames.

SUMMARY OF THE INVENTION With these and other objects in view, as will hereinafter become apparent, the invention in one of its basic aspects provides a base frame for a printing press which essentially consists of two upright sidewalls spacedly parallel to each other and a connecting cylindrical tube having a horizontally extending axis and respective axially terminal portions fixedly fastened to the sidewalls. Good rigidity may be had with such an arrangement if the diameter of the connecting tube is at least one-quarter, and preferably not substantially less than one half of the height of the sidewalls, so that the drive motor ofthe press may be installed in the tube.

The rigidity of such a press frame is very high even if the tube constitutes the sole effective structural connection between the sidewalls. The weight of the tube should be equal to or greater than that of either sidewall, and not substantially smaller than the weight or either sidewall if the base frame is desired to combine minimum weight with greatest stability.

If printing implements of the press, such as feeders are operated by air pressure different from atmospheric pressure, so that the press needs to be equipped with an air pump, the pump should also be installed in the tube for minimizing vibrations.

Other features, additional objects, and many of the attendant advantages of this invention will readily be appreciated as the same becomes better understood by reference to the following description of a preferred embodiment when considered in connection with the appended drawing.

BRIEF DESCRIPTION OF THE DRAWING In the drawing:

FIG. 1 shows the base frame of an offset printing press and associated elements in side elevation; and

FIG. 2 shows the frame of FIG. 1 in plan view.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing in detail, there is shown as much of an offset printing press of the general type illustrated and described in Photo-Offset Fundamentals by John E. Cogoli (McKnight & McKnight Publishing Co., Bloomington,

LII

III., 1960, pages 158 et seq.) and commercially available as ATF Chief 20 Press." as is needed for an understanding of this invention. The actual printing implements such as the cylinders, the dampening and inking mechanisms, and the paper feeding and delivery devices have been omitted since they may be entirely conventional and are not directly relevant to this invention.

The drawing thus is mainly concerned with the base frame itself which consists of two upright, spacedly parallel sidewalls 1,2 and a large horizontal steel tube 3 connecting the sidewalls. The sidewalls 1,2 each have upright front and rear members 11,12 of rectangular steel tubing connected by upper and lower longitudinal members 12,14 of the same material. Triangular webs or ribs 21 of sheet steel are provided in the corners of the rectangle formed by the members 11,12, 13,14, and two webs 22 which connect the center portions of the longitudinal members 13,14 jointly have the shape of a rectangular plate formed with a large circular opening in its center. The elements of each sidewall are welded to each other.

The axial ends of the cylindrical tube 3 are welded to the longitudinal members 13,14 and to the webs 22 and thereby fixedly connect the two sidewalls. The drawing is substantially to scale, and it is evident from the drawing that the diameter of the tube 3 is greater than one-half the height of the sidewalls. Because of the rigidity afforded to the illustrated base frame by the large tube 3, the tubular members 11,12, 13,14 of the sidewalls 1,2 can be made of relatively light-gage material so that the walls 1,2 are each lighter than the tube 3.

Two elements of the printing press which are primary potential sources of vibration, a compressor 5 and the electric drive motor 6 of the press are mounted within the tube 3 on a conventional adjustable support 7, and are effectively prevented from affecting the quality of the printed work. A belt 61, only partly seen in FIG. 1, connects the drive motor 6 to the superstructure of the press which includes the printing implements. The printing implements comprising a cylinder C, dampening and inking rollers I, pneumatic paper feed, P, connected by conventional means to the compressor 5 and a print delivery unit D, (all of which are shown schematically in FIG. 1) are mounted on a subsidiary upper frame normally attached to pads 4 on the illustrated base frame which are arranged in a common support plane.

As is best seen in FIG. 2, the tube 3 and the front portions of the sidewalls 1,2 bound a space which is open in a forward, upward, and downward direction, and a similar rearwardly open space is bounded by the rear portions of the sidewalls and the tube. These open spaces are conveniently available for installation of the paper feed and paper delivery devices of the press, and thus permit the press to be made very compact.

We claim:

1. In a printing press having a base frame, support means thereon for mounting printing implements, a drive motor, and motion transmitting means for connecting said motor to the printing implements for operating the same, the improvement in the base frame which comprises:

a. two upright sidewalls spacedly parallel'to each other;

b. said support means resting on the upper edges of said walls for carrying said printing implements;

c. a cylindrical hollow tube constituting the sole structural connection between said sidewalls, said tube having a horizontally extending axis and respective axially terminal portions of said tube being fixedly fastened to said sidewalls to form a rigid base, the diameter of said tube being at least one-quarter of the height of each sidewall, and sufficient to mount at least said drive motor therein;

d. and means for adjustably supporting said drive motor within said tube, said drive motor 'being mounted on said support within said tube.

2. In a press as set forth claim 1, further including an air compressor for supplying said air pressure, said compressor being mounted on said support within said tube.

3. In a press as set forth in claim 1, the diameter of said tube being substantially equal to one-half of said height.

4. In a press as set forth in claim 1, the weight of said tube being substantially equal to the weight of one of said sidewalls.

5. In a press as set forth in claim 1, said tube and said sidewalls bounding two spaces open in an upward and downward direction and respectively open in opposite 5 horizontal directions longitudinally of said sidewalls. 

1. In a printing press having a base frame, support means thereon for mounting printing implements, a drive motor, and motion transmitting means for connecting said motor to the printing implements for operating the same, the improvement in the base frame which comprises: a. two upright sidewalls spacedly parallel to each other; b. said support means resting on the upper edges of said walls for carrying said printing implements; c. a cylindrical hollow tube constituting the sole structural connection between said sidewalls, said tube having a horizontally extending axis and respective axially terminal portions of said tube being fixedly fastened to said sidewalls to form a rigid base, the diameter of said tube being at least one-quarter of the height of each sidewall, and sufficient to mount at least said drive motor therein; d. and means for adjustably supporting said drive motor within said tube, said drive motor being mounted on said support within said tube.
 2. In a press as set forth claim 1, further including an air compressor for supplying said air pressure, said compressor being mounted on said support within said tube.
 3. In a press as set forth in claim 1, the diameter of said tube being substantially equal to one-half of said height.
 4. In a press as set forth in claim 1, the weight of said tube being substantially equal to the weight of one of said sidewalls.
 5. In a press as set forth in claim 1, said tube and said sidewalls bounding two spaces open in an upward and downward direction and respectively open in opposite horizontal directions longitudinally of said sidewalls. 